Serum immunofixation electrophoresis with negative k-chain indicates that malignant monoclonal immunoglobulin may not be present, but this test alone is not a complete exclusion, and further refinement of relevant tests as prescribed by the physician is needed to clarify the diagnosis.
Serum immunofixation electrophoresis refers to the separation of various protein components in serum, which is used to differentiate the types of proteins. It is commonly used in the auxiliary diagnosis of various immune diseases such as monoclonal immunoglobulin proliferative disease, Benjamin’s protein and free light chain disease, heavy chain disease, multi-component monoclonal immunoglobulin disease, oligoclonal in localized protein profile, polyclonal immunoglobulin disease, and so on.
Serum immunofixation electrophoresis is one of the commonly used methods to examine monoclonal immunoglobulinemia. Using antibodies that directly recognize heavy and light chains, it distinguishes whether the increased immunoglobulins are monoclonal or polyclonal and identifies the specific type. It also confirms the presence of monoclonal immunoglobulins and is indicated for monitoring the efficacy of treatment for monoclonal immunoglobulinemia.
The k chain, or kappa chain, is one of the types of light chains. There are two types of light chains, kappa and lambda, and the normal ratio of the two in the body is 2:1, i.e., the total number of kappa light chains is twice as large as the number of lambda light chains. k-chain negativity is often indicative of an increase in immunoglobulins that are polyclonal, rather than malignant monoclonal.
To diagnose monoclonal immunoglobulinemia, a combination of serum free light chain and serum protein electrophoresis is needed to improve the early diagnosis of monoclonal immunoglobulinemia.
It is recommended to standardize the interpretation of the report under the guidance of a physician.